Blood Lines
by UnderWorldQween
Summary: John Watson always asummed the scars on Sherlocks arms were track scars. He never imangined he or his flat mate were anything but human. He was wrong. Xover with The Mortal instruments


**Disclaimer:** Sherlock, BBC and the Mortal Instruments series belong to their respective owner(s). Anything else that you recognise as copyright censored also belongs to their respective owner(s). This message is effective throughout the entire fanfic.

1. Discarded Notions.

::Prologue::

John Watson was, unknowingly, a downworlder.

Several generations ago, his great-times-_x_ Grandmother had a thing with a pixie. This creature blood had, by the time it reached John, been diluted enough that its only remaining attributes were a love for rainy weather, a hatred of lying, his deep and steady calm as a doctor, and, theoretically, the sight. Though John had never really been able to _see_, he _saw_ enough to be able to detect the tracings of feathery scars on the back of his flat-mate's hands, but he, thinking both he and his flat mate normal, had never questioned them nor Sherlock's complete skin coverage.

Gregory. M. Lestrade was a werewolf.

He was one of the tiny percentages that have not, in fact, been turned, but born. This offered him a level of control that was unavailable to a majority of turned lycanthropes. This also made him completely safe to be around in the mundane world, and, therefore, to be a D.I. His wolf senses, such as sight and smell, took him from being a good investigator to a great one picking up traces others had missed. On the other hand, though, he had looked Sherlock over and pronounced him human, brilliant, but human. He had dismissed Sherlock's searching eyes as _unseeing_, had ignored Sherlock occasional use of the angels name and, like John, discarded the etched lines on Sherlock's arms as track scars. Sherlock had, after all, been a junkie. _Anderson_ was the one that needed to be watched around the corpses; he was a kelpie.

When John Watson woke up that morning, he hadn't expected to be facing death. He should have been, after all, he saw death every day. He did, of course, live with Sherlock Keeper-of-Body-Parts-in-the-Bloody-Kitchen Holmes.

The day had been like any other day, dreary and overcast. Sherlock had dragged him out of bed at 5:30 to go stare at a dead person, and now John stood hand shoved deeply in his pockets blinking blearily at an equally muzzy-looking Detective Inspector. Sherlock, of course, was bright-eyed and bushy-tailed, impeccably dressed and flitting around the crime scene like an overgrown bird on caffeine while Anderson looked on hatefully. The body, though, to give it credit, was a touch unusual, male, about thirty-five, deep chestnut hair, pale skin, naked except for what looked like some silver jewelry, and _covered_ in lacerations. That was all normal enough. What was odd was the thing that looked like a massive bite wound that had been taken out of the corpse's side. Sherlock suddenly stood stock-still eyes following a trail in the air, none of which the others could follow. This usually meant he had something and the DI took his cue.

"Found anything, Sherlock?" Lestrade's voice sounded hoarse as if he hadn't slept much. Sherlock's eyes snapped to the inspector, something like amusement frolicking in their depths as he eyed looked the inspector up and down.

"Oh plenty, had fun last night Lestrade? Hyde Park is lovely at night."

"I meant about the _murder_, Sherlock!" There was a tone in Lestrade's voice that John had never heard, almost a 'ha-ha I know something you don't'. It seemed reflected in Anderson's larger-than-normal sneer, but Sherlock appeared almost mischievous.

"Nope can't help you!" Sherlock sounded positively gleeful. "It's not your jurisdiction, anyway." Ignoring Lestrade's sputter of protest, he continued, "Come on John! This case is far too _mundane_for me." With that, he turned, coat flaring, and strode away, leaving a confused John and Inspector behind.

Hours later, when John was about to leave to go shopping, Sherlock did something he never had before. _H__e asked if he could come._

John stared, slack-mouthed, and asked, "Why?"

His strange grey eyes serious, Sherlock pivoted.

"Tonight isn't a good night to be alone in the dark, John."

Unnerved by the detective's peculiar response, John simply nodded and the pair went to Tesco's.

**A/N** This is to my knowledge thus so far the only Sherlock/Mortal instruments fic… Sooo let me know what you think! Flames will be used to keep my frozen feet warm, April showers my ass


End file.
